Kotlin Academy · Lesson

Declaring Data Classes

Concise model classes.

Classes for Holding Data

Many classes exist only to bundle a few values together: a user, a point, a result.

Kotlin gives you the data class, a concise way to declare such model classes with lots of free behavior.

Add the data keyword before class and list the properties in the constructor.

That single line gives you a fully featured model.

data class User(val name: String, val age: Int)

fun main() {
    val u = User("Alice", 30)
    println(u.name)
    println(u.age)
}